The present invention relates to a hydroprocessing catalyst, to the method for the preparation thereof and to the use of this catalyst in a method of hydroprocessing and/or hydrocracking hydrocarbons, in particular hydrocarbons derived from petroleum fractions with a boiling point range of between 40 and 560° C.
Currently, the demand for desulfurized, denitrogenated and dearomatized hydrocarbon compounds is increasing and manufacturers are developing catalysts which are increasingly effective with respect to the purification of hydrocarbons. However, these new catalysts are much more expensive and are accessible only from a limited number of producers. In addition, from their first regeneration, these catalysts exhibit an activity that is often much lower than their initial activity in the fresh state under the same operating conditions. An additional specific rejuvenation treatment sometimes makes it possible to recover an activity similar to the initial activity and thus makes it possible to reuse the catalyst for a further cycle of deep hydrodesulfurization and the production of distillates having sulfur contents of less than 10 ppm. Several rejuvenation treatments are proposed on the market.
They generally combine regeneration steps under specific conditions, and chemical and thermal treatments, and can be associated with ex situ sulfurizations of the catalyst.
Numerous “conventional” catalysts, based on carriers formed of refractory oxide(s) and containing a combination of group VIB and VIII metals are today used in refineries, in the fresh or regenerated state, either in hydroprocessing or in hydrocracking. If it proves to be impossible to significantly increase their activity in desulfurization and/or denitrogenation, these catalysts will have to be recovered, stored or destroyed when the specifications imposed with regard to fuels become so restrictive that it will no longer be possible to use them. This storage or elimination of solids could also be subject to environmental and safety restrictions and could generate significant additional costs for refiners.